1. Field of the Invention
The present invention relates to a method for manufacturing a packaged, aseptic hard soybean curd.
2. Description of the Related Art
Reflecting the recent trend of the public toward a healthy food life, soybean products, especially, a soybean curd called "TOFU" has come to be attractive and cooking thereof has been diversified. Furthermore, an increased tendency to utilize soybean curd as one of the materials for cooking is seen lately. Thus, a demand has developed for a hard soyubean curd which has the fine texture of "kinugoshi" type (silky and soft texture) and is still harder than conventional fine textured soybeam curd. Such a demand is depend on harder soybean curd which is suitable formixing with other foods without markedly getting out of shape and is easy to handle in cooking. It has been known that hardness of soybean curds can be increased by using a soybean juice of high protein content or by increasing additional amount of coagulating agent and furthermore, there has been a known method for producing a soybean juice of high protein content which comprises adding a soy protein isolate to a soybean juice and subjecting the soybean juice to a homogenizing treatment as disclosed in Japanese Unexamined Patent Publication Gazette No. 78559/1983. However, according to this method which uses general soy protein isolate to produce a soybean juice of high protein content, hardness of the produced soybean curd is still insufficient. When amount of the soy protein isolate is increased to obtaint he desired hardness, there is the problem in process that dispersion and dissolution of the soy protein isolate become difficult. Thus, there have been limitations in increasing hardness of soybean curds. In addition, it has been said that with heating conditions becoming severer such as heat sterilization, curd tension decreases. On the other hand, mere increase of additional amount of coagulating agent to increase hardness causes extreme deterioration of taste and this method cannot be employed.
At present, imparting a sufficient harndess to a sterile soybean curd has not yet been accomplished.